Ship Noise Disrupts Feeding for Common Shore Crabs

A latest study reveals that the noise from passing ships disrupts feeding for the common shore crab.

The issue of human generated sounds and their effect on the marine life has gained a lot of public as well as scientific interest.

Researchers from Universities of Exeter and Bristol noticed that on being threatened by loud noises produced by ships, the crabs took longer to get back into their shelter and did not use their natural 'play dead' behavior.

Shore crabs or Carcinus maenas can tolerate a wide range of salinities and cannot cross deep water. It was noticed that quiet harbor sounds did not distract the crabs but human generated sounds including construction activities and passing ship sounds did disturb their feeding.

"Crabs feeding on mussels were often distracted when ship noise was playing compared to quiet harbour recordings. Furthermore, crabs took longer to retreat to shelter after simulated attacks in noisy treatments, and if turned upside-down they flipped back far quicker in noisy conditions rather than turning slowly to avoid attracting attention of potential predators," said Matt Wale from the University of Bristol.

According to Dr Steve Simpson from Biosciences at the University of Exeter, it is already known that the metabolic rate and energetic needs of crabs intensify with the increase in ship noise. With reduced foraging and severe responses to predators, the survival of these crabs will be impacted, which will eventually have an adverse affect on the ecosystem, he adds.

The study was published in the journal Animal Behaviour.